Queries to help warm up (mmap)

[Rallavagu]

Looking for clues/recommendations to help warm up during startup. Not 
necessarily Solr caches but mmap as well. I have used some like 
"q=<field name>:[* TO *]" for various fields and it seems to help with 
mmap population around 40-50%. Is there anything else that could help 
achieve 90% or more? Thanks.